1. Field
Exemplary embodiments relate to a wireless communication, and more particularly, to a method and apparatus for controlling a transmit power in wireless communication system.
2. Discussion of the Background
3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) uses an orthogonal frequency division multiple access (OFDMA) in a downlink and uses a single carrier-frequency division multiple access (SC-FDMA) in an uplink. Recently, discussion on 3GPP LTE-Advanced (LTE-A) corresponding to an evolved form of the 3GPP LTE is in progress.
Device-to-device (D2D) communication refers to a distributive communication technology that enables adjacent user equipments (UEs) to directly transfer traffic. In the D2D communication, a UE, such as a mobile phone, autonomously searches for another UE physically adjacent to the UE, sets up a communication session, and transmits traffic to the found UE. The D2D communication may outperform a traffic overloading issue by distributing traffic concentrated on an evolved NodeB (eNB). D2D communication technology, such as Bluetooth or wireless fidelity (Wi-Fi) direct, supports direct communication between radio nodes without using support of the eNB.
Controlling of transmit power is essential for D2D communication. The transmit power is required for interference mitigation and power saving. When the transmit power of a UE is relatively very low, a peer device may not readily receive data. On the contrary, when the transmit power of the UE is relatively very high, a large amount of interference may occur in another device. In addition, a significantly high transmit power may increase an amount of battery used.